Cyanogen chloride is an extremely toxic gas, so its removal from respirable air is highly desirable. Certain amines, for example, triethylenediamine, have been found to be capable of removing cyanogen chloride, and are often used in combination with (e.g., incorporated on) sorbent materials such as activated carbon, in applications such as respiratory protection.
Carbon monoxide is also toxic, so its removal from respirable airstreams is also highly desirable. Various materials and substances (e.g. the well-known Hopcalite catalyst, and certain metal catalysts, for example, gold), have been found to be capable of catalyzing the oxidation of carbon monoxide to carbon dioxide and have been proposed for various respiratory protection applications.